The Boy and the Heron, reportedly the final film from Japanese master animator Hayao Miyazaki, has taken the number one spot at the box office on its North American release, as well as achieving record figures for the director.

Preliminary box office returns report that The Boy and the Heron took $12.8m in the US and Canada on its opening weekend, putting it a significant distance ahead of The Hunger Games: The Ballad of Songbirds and Snakes, which managed $9.4m. In third place was another Japanese film, the monster movie Godzilla Minus One, on $8.3m.

Inspired by a novel by Genzaburō Yoshino, The Boy and the Heron is the story of a troubled child who ends up in a mysterious fantasy realm after his mother dies, and follows Miyazaki’s last film The Wind Rises, after which Miyazaki “retired” in 2013. Miyazaki is yet to make a statement over any future projects, but a recent Guardian report from Studio Ghibli in Tokyo, the director’s production base, suggested that rumours of this being his final film are indeed true: the studio has no films on its slate and all production activity appears to have ceased.

Miyazaki’s highest-grossing film in North America is currently Ponyo, which earned a total of $15.1m on its release in 2009, which The Boy and the Heron is well on course to beat. Miyazaki’s Oscar-winning animation Spirited Away took a total of $10m in the US and Canada in 2002, but like all of the director’s films, Spirited Away proved far more popular outside the US, with a total global box office of $383.9m.

The Boy and the Heron was released in Japan in July with almost no promotion other than a single poster image, with producer Toshio Suzuki commenting at the time that “Deep down, I think this is what moviegoers latently desire.” It has since earned over ¥8.2bn ($56.2m) in its home country.